cbfs: Support reading compression information

CBFS now supports compressed filed. Add support for reading this
information so that the correct decompression can be applied. The
decompression itself is not implemented in CBFS.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 22 insertions, 0 deletions

diff --git a/fs/cbfs/cbfs.c b/fs/cbfs/cbfs.c
index 9e534d15f2..443a148e3f 100644
--- a/fs/cbfs/cbfs.c
+++ b/fs/cbfs/cbfs.c
@@ -91,6 +91,7 @@ static int fill_node(struct cbfs_cachenode *node, void *start,
 		     struct cbfs_fileheader *header)
 {
 	uint name_len;
+	uint offset;
 
 	/* Check the header is large enough */
 	if (header->offset < sizeof(struct cbfs_fileheader))
@@ -104,6 +105,27 @@ static int fill_node(struct cbfs_cachenode *node, void *start,
 	node->name = start + sizeof(struct cbfs_fileheader);
 	node->name_length = name_len;
 	node->attr_offset = header->attributes_offset;
+	node->comp_algo = CBFS_COMPRESS_NONE;
+	node->decomp_size = 0;
+
+	for (offset = node->attr_offset; offset < header->offset;) {
+		const struct cbfs_file_attribute *attr;
+		uint tag, len;
+
+		attr = start + offset;
+		tag = be32_to_cpu(attr->tag);
+		len = be32_to_cpu(attr->len);
+		if (tag == CBFS_FILE_ATTR_TAG_COMPRESSION) {
+			struct cbfs_file_attr_compression *comp;
+
+			comp = start + offset;
+			node->comp_algo = be32_to_cpu(comp->compression);
+			node->decomp_size =
+				be32_to_cpu(comp->decompressed_size);
+		}
+
+		offset += len;
+	}
 
 	return 0;
 }